GULF WAR WEAPONRY CLAIMS FAR OFF-TARGET, REPORT SAYS.

Byline: Tim Weiner The New York Times

During and after the Persian Gulf War, the Pentagon dramatically oversold the effectiveness of its most expensive high-tech aircraft and missiles, the most thorough independent study to date has found.

The Pentagon and its principal military contractors made claims for the pinpoint precision of their most impressive new weapons - the Stealth fighter jet, the Tomahawk land-attack missile and laser-guided ``smart bombs'' - that ``were overstated, misleading, inconsistent with the best available data, or unverifiable,'' the study by the nonpartisan General Accounting Office found.

The accounting office concluded that new, costly ``smart'' weapon systems did not necessarily perform better in the Persian Gulf War than old-fashioned, cheaper ``dumb'' ones. It called into question the wisdom of the military's plans to depend increasingly on weapons that extend the state of the art of war at a cost of tens of billions of dollars.

The accounting office analyzes government programs for Congress. Its secret four-year study of the air war conducted during Operation Desert Storm is the most detailed analysis of its kind to be made public.

It used more than one million pieces of information: Defense Department databases compiled for commanders, intelligence reports, after-action analyses and reports from military contractors. The accounting office also interviewed more than 100 Desert Storm pilots, war planners and battlefield commanders.

An unclassified summary of the 250-page secret report is scheduled to be published this week. The report was commissioned in 1992 by Sen. David Pryor, D-Ark., and Rep. John D. Dingell, D-Mich., to help Congress decide what weapons to buy in the future.

The secret report contains facts and figures to buttress the 13-page unclassified summary, which was made available to The New York Times by a government official familiar with the underlying report.

During the war, Pentagon briefers treated the public to videotapes showing a smart bomb diving down the air shaft of a Baghdad building and told anecdotes about the extraordinary accuracy of Tomahawk missiles launched from afar. The study concluded that while some of those stories were true, they were not the whole truth.

Nor is this the first time that praise for Pentagon weaponry made in the flush of victory in the Gulf War has been questioned.

In 1991, President Bush said the Patriot missile system had been nearly perfect, shooting down 41 out of 42 Iraqi Scud missiles aimed at Israel and Saudi Arabia.

Defense Department officials later said that the Patriot was far from perfect, knocking out perhaps 40 percent of the Scuds aimed at Israel and 70 percent of those aimed at Saudi Arabia. Skeptics - congressional investigators, Israeli officials and a Massachusetts Institute of Technology scientist - said the Patriot may not have scored more than one clean hit.

The Pentagon did not dispute the new report's main conclusions. In an April 28 letter to the accounting office, the Defense Department said it ``acknowledges the shortcomings'' of its precision-guided munitions, the aircraft that carry them, the Tomahawk missiles and the department's ability to assess the effectiveness of its bombing campaign in the Gulf War.

It said it would deal with those shortcomings by building improved smart weapons, studying whether it has the right mix of weaponry in its arsenal and proposing new ways to locate and destroy targets.

American air power overwhelmed the Iraqi military during the 1991 Persian Gulf War, and helped win that famous victory. The United States deployed nearly 1,000 combat aircraft and unleashed nearly as many tons of bombs each day as were dropped on Germany and Japan daily during World War II.

But for all their superior technology, pilots often could not tell whether a presumed target was a tank or a truck or whether it already had been destroyed, the report said. Their sensors - laser, electro-optical and infrared systems - could not see clearly through clouds, rain, fog, smoke or high humidity, the report said.

The sleek black F-117 Stealth fighter jet, despite its high cost and its highly touted ability to get close to a target while evading detection, did not necessarily outperform older, cheaper aircraft. (The fighters cost more than $106 million each in 1990; the plane is different from the B-2 Stealth bomber, which has never flown in combat and costs more than $2 billion a copy thus far.)